Improved dibenzanthrone and process for its manufacture



IMPROVED DIBENZANTHRONE AND PRGCESS FOR ITS MANUFACTURE Ralph Norbert Lulek, Milwaukee, Wis, assignor to E. l. du Pont de Nemours & Company, Wilmington, DeL, a corporation of Delaware No Drawing. Application March 10, 1932, Serial No. 598,091

8 Claims. (Cl. 260-61) This invention relates to chemical compounds Example I and more particularly to substances useful as vat dyes and vat dye intermediates. It especially re Ten (10) parts of the dry oxidation product of lates to derivatives of oxidized dibenzanthrone. dibenzanthrone prepared according to U. S. P.

The synthetic dyestuff industry is approxi- 1,093,427 by the oxidation of dibenzanthrone with 6D mately seventy-five years old having been initimanganese dioxide and boric acid in concentrated ated by Perkins discovery of Mauveine in 1856. sulphuric acid which had been treated with so- During the life of this industry research has been dium bisulphite to remove the manganese dioxide carried out on a most extensive scale and progwere heated with 200 parts of fused sodium sul- 10 ress has been very rapid and wide spread. The phide with good agitation at 130160 C. for 3 5 field is now so broad as to practically preclude hours. The melt was then boiled for minutes any one person being a specialist in more than with 1500 parts of water, filtered, washed with one phase of the industry. The expansion of the water and alcohol and dried. The greenish-black industry has been greatly aided by its literature powder obtained is believed to be the sodium salt 15 accumulation which is now most extremely voof dihydroXy-dibenzanthrone since it contained 7 luminous. This is well shown by the list of the by analysis 8.3% of sodium and would have con- United States dye patents which was published tained according to theory 8.6%. The product is at the end of 1923 by Doyle. This list is a book soluble in concentrated sulphuric acid with a comprising approximately 600 pages. Although violet color and in hot water and pyridine with a certain natural vat dyes were known before Pergreen color. It gives blue alkaline hydrosulphite 75 kins discovery above referred to, the developvats from which cotton is dyed in bright yellowments in this field have been particularly promigreen shades. When the mildly reduced oxidanent since the discovery of Indanthrone in 1901 tion product prepared according to U. S. P. 1.093,- by Bohn. In spite of the great age of this indus- 427 is similarly treated the same product results.

try, the extensive research and literature accumulation, there has been but one green anthra- Example H quinone commercially successful vat dye pro- Ten (10) parts of di-hydroxy-dibenzanthrone duced. This dye is commercially known as Ponwere heated to boil with a solution of 100 parts sol green G (C. I. 1101) and is produced by the of sodium sulphide in 300 parts of water. After acylation or alkylation (U. S. P. 1,531,261) of the boiling for one hour the mass was filtered, oxidation and mild reduction (U. S. P. 1,093,427) washed with salt water and dried. The comproduct (hereinafter referred to as di-hydroxypound produced was apparently identical with dibenzanthrone) of dibenzanthrone. This inventhat obtained in Example I. tion particularly deals with new processes for The oxidized but not mildly reduced product 35 the preparation of Ponsol green G. of U. S. P. 1,093,427 may be similarly treated. v

This invention has for an object the production It is to be understood that the invention is not of new chemical compounds and processes and in limited to h Productlon 0f the sodium Salt o general an advancement in the art other dihydroxy-dibenzanthrone. If desired the pojects will appear hereinafter. tassium or other alkali metal salts may be pre- 40 These objects are accomplished by isolating pared and named the alkali metal salt of oxidized and mildly refi i gl ififi and clams the duced dibenzanthrone, and if desired further term me 5a 15 vised to h ammonium (NH4 salts which are similar in treating the isolated alkali metal compound to their reactions to the alkali met 1 the Ponsol green G type previ- 4' ploduce dye of Other alkali metal sulphides or poly-sulphides 9 referred: Thls ,furthel treatment may than those of sodium may be used in the process lnvolve acylation, alkylatlon or analogous treatdescribed merit Of t Isolated alkah meta1 cmpmmd If desired the treatment of the dibenzanthrone it may involve treatment of the isolated alkali derivative with aqueous alkali metal sulphides 50 metal compound with acid and Subsequent acyla" (or poly-sulphides) may be carried out in autotion, alkylation or analogous treatment of the C1aves t t er tures exceeding ithe boiling acid treated product. The invention will be furpoint of th l ti ther understood from a consideration of the fol- By treating the alkali metal salts produced lowing examples in which the parts are given by according to the above examples with dilute 55 weight. mineral acids, for example, hydrochloric acid,

free di-hydroxy-dibenzanthrone which is a dark blue powder, is produced.

The invention herein described has numerous advantages over the art as exemplified in the patents previously mentioned. The dyeings made with the alkali metal salts of the di-hydroxydibenzanthrone are brighter and generally superior to those produced by the product of U. S. P. 1,093,427. The same is true of the dyeings made with the dihydroxy-dibenzanthrone produced from the alkali metal salt products of this invention.

The alkali metal compounds produced according to this invention are very reactive, and may be acylated or alkylated (for example, methylated with di-methyl-sulphate) with great ease. The resultant products give dyeings which are superior to the dyeings made from the products of U. S. P. 1,531,261. Generally superior dyeings are also produced from the acylated or alkylated dihydroxy-dibenzanthrones produced in accordance with the above.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that I do not limit myself to the specific embodiments thereof except as defined in the appended claims.

I claim:

1. A process for producing alkali metal salts of dihydroxy-dihenzanthrone which comprises treating oxidized and mildly reduced dibenzanthrone with an alkali metal sulfide or poly-sulfide, and separating the alkali metal salt from the reaction mass.

2. A process for producing the sodium salt of dihydroxy-dibenzanthrone which comprises treating oxidized and mildly reduced dibenzanthrone with sodium sulfide or poly-sulfide, and

separating the sodium salt from the reaction mass.

3. A process for producing the sodium salt of dihydroxy-dibenzanthrone which comprises treating oxidized and mildly reduced dibenzanthrone with sodium sulfide and separating the sodium salt from the reaction mass.

4. A process for preparing dihydroxy-dibenzanthrcne which comprises treating oxidized and mildly reduced dibenzanthrone with an alkali metal sulfide or poly-sulfide, separating the resulting alkali metal salt of dihydroxy-dibenzanthrone and treating it with an acid to form dihydroxy-dibenzanthrone.

5. A process for preparing dihydroxy-dibenzanthrone which comprises treating oxidized and mildly reduced dibenzanthrone with an alkali metal sulfide or poly-sulphide, separating the resulting alkali metal salt of dihydroxy-dibenzanthrone and treating it with a dilute acid solution to form dihydroxy-dibenzanthrone.

6. A process for preparing dihydroxy-dibenzanthrone whi h com rises treating oxidized and mildly reduced dibenzanthrone with sodium sulfide, separating the resulting sodium salt of dihydroxy-dibenzanthrone and treating it with a dilute mineral acid solution to form dihydroxydioenzanthrone.

'7. A process for preparing alkali metal salts of dihydroxy-dihenzanthrone which comprises treatin dihydroxy-dibenzanthrone with a memer selected from the group consisting of an alkali metal sulfide and an alkali metal poly-sulfide.

8. A process for preparing the sodium salt of dihydroxy-dihenzanthrone which comprises treating dihydroxy-dibenzanthrone with sodium sulfide.

RALPH N. LULEK. 

